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Focus Stacking Adventures Part I

Before starting I highly recommend to take a look at extreme-macro If you still did not. I also want to thank Johan J Ingles-Le Nobel for this fantastic web-site and sharing his invaluable experiences which helps the community a lot.

When I started to macro photography a couple of years ago, I was not aware that how it might become so complicated this quickly. After a couple months sneaking in our apartments backyard with a lot of weird looking equipment, I decided to give it a try to deep focus stacking which I was thinking “very unnecessary” at first. This is why, I will start first with why and when Focus Stacking is necessary.

Focus Stacking: or how taking a single photo can become the most tedious job on earth

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Newport 423 has a manual Micrometer

When you take a photo, the thing that determines the depth of field (how much of the picture is in focus) is the aperture. As the diaphragm narrows, depth of field increases, thus more light needed. That is why most macro photographers uses hand flashes during daytime in the field, even under bright sunlight. I wont go into deep math, that is totally another topic, but you need lots of light to shoot a 2:1 or even a 1:1 macro shot with an acceptable depth of field. However, as I mentioned, even this problem can be solved with flashlights and relatively higher iso values, there is something else that ruins the image. That is called diffraction.

What most beginners (or even sometimes intermediate photographers) don’t know is that higher aperture values (means narrower diaphragms) creates wider depth of fields but as the aperture goes high the image loses sharpness. Every lens has a sweet spot which the sharpest image that particular lens can shoot. Most of the time it is 1 or 2 stops above the widest aperture.

The desperate need of this precious sharpness is my motivation to jump into the focus stacking. Which I am still falling.

Focus Stacking is basically combining two or more images to create wider depth of fields. Although Adobe Photoshop can do that, there are also specific softwares for that purpose like Zerene Stacker and Helicon Focus.

The problem is, when the initial depth of field is as narrow as an edge of razor blade, you will need much more than a couple of images, sometimes hundreds of them. It is impossible to change the focus with that precision. In fact, the only professional dedicated macro lens Canon mpe-65 does not even has a focus ring. When we are in the macro world to change the focus you need to physically move the camera. For over 1:1 magnifications the distances you need to move the camera is so small that it is not even noticable from outside. In my most frequent setup, the distance is about 1/10 mm. So here we need some special equipment.

The majority of People use a linear stage called Newport 423 single axis linear stage for macro stacking. This is a manual stage which you manually turn a micrometer which moves the plate for as less as 0.01mm. The problem with manual stackers are you have to fix everything very solid or else when you are in the middle of the stack, with one hurried movement you can ruin everything. And much more importantly, you have to do everything manually… Which means over a hundred shot… For a single image… manually…

So honestly I did not used Newport 423 (I tried some other manual methods however) but I was sure that my patience is not strong enough for that. So there were two way ahead: Either I would forget about studio stacking or I would find a “automated solution”.

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One of my first automated slider attempts. There is a camera connection, but it is not powerful or balanced enough to move the camera

First I started with very pathetic workarounds. Instead of moving camera, I used old CD-ROM trays to move the object.

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Another attempt. This time it is less misarable with a fancy LCD menu

As you may notice in the first picture, I first designed it to move the camera. But it was very weak to move it. In the second one I updated it a little bit with an LCD screen with some fancier menus. Here are the some of the photographs I shot with these rigs:

LadyBug Larvae

Nosferatu

Dry Lemon

Seasoned Model

By the way, these were happening before StackShot or the newcomer Wemacro. In a way I was glad that I never bought one of those for 3 reasons:  1. They are very expensive.  2.My latest solution FocusStacker v3 is much better, precise and also better looking (FocusStacker v4 is on the way it will make some people very jealous). 3. And finally, sometimes the quest itself is more important then the mission. I probably enjoyed -and still do- much more when building equipments then using them.

There are some obvious problems and limitations if you move the subject instead of the camera.

First of all, ideally you have to move the lights too along with the subject, so there wont be any shadow and reflection changes between shots. I dont know what would make moving the lights logical if we were moving the subject because of the weight and stability reasons at the first place. So I mark that out of question and skip it.

Second, it is not artist friendly. Meaning that it is very very hard to make a good picture with that kind of setup. The movement direction of the subject and camera should always stay in one axis. Once you put your camera and tray on a imaginary line, you cannot move them again. This will make you feel very limited when your view is locked down on a single angle you will always feel the urge to move the subject “juuuuusssst a little bit”. Which ends most of the time falling the subject down and losing one antenna…

Third, it is indoor only. There is no way to use this pathetic thing outside. Your subject must be dead or inanimate object. On the other hand -even if it is very hard for me- it is possible to shoot sleeping or standing objects with a moving camera setup.

This was the FocusStacker© v1

Next: Focus Stacker V2 in deeper detail

 

 

 

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